This invention relates, in general, to electronic device packaging, and more specifically to methods and apparatus for forming interconnects in flip-chip packages.
Flip-chip microelectronic packaging technology has been in existence for more than 30 years, and involves a direct electrical connection of downward facing (hence, “flipped”) electronic components or chips to substrates, circuit boards, or carriers. The electrical connection is made through conductive bumps or balls connected to bond pads on both the chip and the substrate. In contrast, wire bonding, which is an older technology, uses upward facing chips with a wire connection between each bond pad and a corresponding lead or pin on a lead frame.
Flip-chip components are predominantly semiconductor devices. However, components such as passive filters, detector arrays, and sensor devices are also beginning to be used in flip-chip form. Flip-chip is also referred to as Direct Chip Attach (DCA), a more descriptive term, because the chip is-directly attached to a substrate, circuit board, or carrier by conductive bumps.
Although flip-chip technology has progressed to include a wide variety of materials and methods for bumping, attaching and underfilling devices, challenges still exist in solving problems with tighter space requirements, reduced costs, and enhanced device performance and reliability.
Accordingly, a need exists for improved structures and processes for forming flip-chip type packages.